


Summer Romance

by SprucePines



Category: Gravity Falls
Genre: F/M, Incest, Sibling Incest, Twincest
Language: English
Status: Completed
Published: 2015-09-27
Updated: 2015-09-27
Packaged: 2018-04-23 16:00:42
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,380
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4883014
Author URL: https://archiveofourown.org/users/SprucePines/pseuds/SprucePines
Summary: <blockquote class="userstuff">
              <p>Mabel's decided who her new summer romance is going to be: her brother. Elements of this story were rewritten by pollinating-pines on Tumblr. (Technically, this could be considered Teen, but there's one brief moment that pushes it toward Explicit, so better safe than sorry)</p>
            </blockquote>





	Summer Romance

Dipper and Mabel set their luggage down and looked around the attic. Just the way they had left it the previous summer, albeit with a year’s worth of dust added.  
  
“Doesn’t Grunkle Stan bother to clean up here anymore?” Dipper asked.  
  
“Well, what reason does he have to clean up here?” she asked.  
  
“We’ve been coming for three years straight now,” he pointed out.  
  
“Aw, don’t worry about it, Dip. We’ve battled an army of gnomes, the Summerween Trickster, and a giant robot Gideon. We can take care of a little dust infestation no problem!”  
  
Dipper smiled and nodded. She was right. In the grand scheme of things, a little dust is a silly thing to get bent out of shape about. They set about cleaning, Mabel singing ‘Whistle While You Work’ and ‘A Spoonful of Sugar’ the entire time. By the time she had finished ‘Spoonful’ the attic was more or less dust free.  
  
Retrieving their luggage, they began to unpack. As Dipper began laying out his clothes on the bed, he glanced across the room at Mabel. He had to chuckle. It figured the first thing she unpacked would be her trusty grappling hook.   
  
Even though they were getting older, they didn’t really mind still sharing the attic, in fact they preferred it as they’d gotten a lot closer in recent years.   
  
Things had started off with Mabel, who didn’t let little things like closed doors, or even locked ones (thanks to Gruncle Stan’s lockpicking lessons) stand in the way of talking to Dipper, regardless of what he might be doing. Which had to lead to her seeing the ‘full constellation’ (as she called it) and then her insisting he see her ‘sunrise platter’ (two eggs sunnyside up and The Mabel syrup dispenser-Bam!) to make it fair, which Dipper had weakly tried to beg off as not being something he wanted to see… not fooling either one for a second.   
  
Following that they started sharing their ‘private time’ with each other and some whispered exchanges during it that showed they both had the same interests and thoughts, things that they never would have believed they would have ever said if they hadn’t been watching their sweaty, naked, twin with their hands busy in their lap.   
  
You’d have thought they’d have taken it farther, but for some reason the closest they’d gotten to getting physical with one another was an arm slipped around the other or a kiss on the cheek while watching the other and offering encouragement. They were on the edge of something that could change everything and neither was willing to cross the line into something more in their parents’ house.   
  
Across the room, Mabel was hanging up her posters. Sev’ral Timez had given way to The 4ever Boyz (who Dipper suspected were also genetically engineered). He just hoped their tour didn’t come anywhere near Gravity Falls, or else she might abduct them, too.  
  
“Are you ever going to outgrow your ‘boy crazy’ phase?” he teased.  
  
“What? You think just because I’m still listening to boy bands that I’m still boy crazy?”  
  
“Well, you still haven’t managed to have that epic summer romance you’ve been wanting to have while we’re here.”  
  
Mabel placed her hands on her hips and crossed the floor to her brother. “I’ll have you know, brother dear, that I’ve already decided who my epic summer romance is going to be.”  
  
Dipper’s eyebrows perked up. “Oh yeah? And who’s the ‘lucky’ guy?”  
  
Mabel gave her twin a knowing smile and leaned forward. She brought her hand up and gently poked his chest with a finger. “You, Dipper.”  
  
Dipper’s eyes widened. “What? What makes you—why would—you think—” he stammered.  
  
“Come on, it’s perfect! Who else knows me better than you? And vice versa. It’ll be so much fun!”  
  
Dipper managed to regain his composure. “I’m sorry, Mabel,” he said, “but I can’t be your summer romance.”  
  
“Why not?”  
  
“There are several reasons.” Dipper gently brushed past his sister and descended the stairs. “Please, just put this out of your mind.”  
  
After Dipper was out of sight, Mabel narrowed her eyes. “Oh, we’ll see about that, brother dear.”  
  
0o0o0o0o0o0o0o0  
  
Almost from the get go, Mabel was following Dipper practically everywhere he went. Any hope for privacy was lost. During the day, Dipper would turn around after completing one of Stan’s many chores and there she would be, giving him her widest smile, sweater pulled tight across her chest, posed to stroke his libido and push his every button. Each time, he’d shake his head no and stumble past. Every night before going to bed, Mabel would call over to him and blow him a kiss. Every time, Dipper would scowl slightly before turning away, and every time, Mabel would sigh in frustration before turning in herself.  
  
Several days of this later, Dipper was making his way through the woods. He’d managed to take care of himself when Mabel was busy in the bathroom getting ready for bed for the most part, but this day he couldn’t wait until the evening, she’d worn a pair of his old shorts and a flannel top with nothing on underneath and he’d been hard pressed not to give in, he had to take care of it now before he did something he’d regret.   
  
Luckily, he’d long since discovered the seclusion of the woods around the Shack. Just as luckily, he didn’t see Mabel as he left the Shack. Navigating his way through the trees, he came to his favorite spot, a small clearing surrounded by tall redwoods. In the approximate center sat a large stone. Leaning back against the stone, he lowered his shorts. Just as he was reaching for his hardening member, he suddenly heard:  
  
“AHA!”  
  
Instantly he pulled his shorts back up and covered his bulge. Just in time, as Mabel came stalking out from the trees and made a beeline for him.  
  
“There’s no getting out of this anymore, Dipper.”  
  
“Mabel, I—” he swallowed heavily, his ability to resist her always weakened when she got passionate and focused her attention solely on him.  
  
“That’s enough out of you, broseph. I’ve tried to be patient with you here, but I can’t take this anymore. Why can’t you be my summer romance?!” she demanded.  
  
“Are you still hung up on that?” Dipper lowered his eyes. “I told you, it can’t happen.”  
  
“But why, Dipper?” she begged.  
  
“You mean besides our being siblings?” he said trying to come up with something she’d believe, not wanting to tell her the truth.  
  
“Is it really so wrong?” she asked softly, reaching out and lifting his chin so she could look into his eyes. “Besides, is making me happy for a single summer that bad? I’m not asking for the world here, Dipper or maybe I am. For just one summer let me be your world.”  
  
“But what if I don’t want it to last just for summer?” he said eyes filling with tears.  
  
Mabel paused. She’d expected any number of arguments from Dipper, but not this. Mabel looked at her twin and gasped. He was trembling.  
  
“Summers—S-summers end, Mabel.” He wiped his tears away and brought his eyes back up to look at her. He was fighting desperately to keep from crying. “It’s not that I don’t want to, Mabel. It’s that I don’t want it to end.”  
  
Mabel rushed forward and wrapped her brother in a hug. His own arms clutched her to him. “I’m sorry, DIpper. I had no idea.”  
  
“I could handle you being in a summer fling with another guy. But when you said you wanted one with me…” He made a half choked sound like a wounded animal.  
  
The dam broke and she could feel him shake as he cried. Mabel lifted his face up to hers and brought their lips together in a kiss. They melted into each other as they sank to the ground. Dipper caressed his sister’s cheek while Mabel wiped away his tears.  
  
“Forget what I said before, Dipper. We can aim higher,” she swore. “Summer romances are only called that because at the end of summer the two part… but we don’t have to do that. Stay with me and I swear I’ll make sure summer never ends!”


End file.
